Urinary system Flashcards
Urinary system consists of
Includes kidneys, ureters, urinary bladder, and urethra
Functions of kidneys
Blood filtration, reabsorption and secretion
Acid-base balance
Fluid-electrolyte balance
Hormone production
Blood pressure regulation
Blood filtration, reabsorption and secretion in the kidneys
Through altering plasma composition by
Filtering plasma constituents from the blood
Selectively reabsorbing water and useful components
Secreting waste products as urine
Acid base balance is done by the kidneys by
Eliminates hydrogen and bicarbonate ions in urine
How do kidneys regulate acid-base balance
Controls water and electrolytes, removing them from blood to equal amount being put in
Correct water to maintain healthy internal environment, through
Diuresis (excess water so more urine formed)
Oliguria (insufficiency of water so less urine formed)
Anuria (deficiency in water so no urine formed)
Under hormonal control (function of the endocrine system) – ADH and aldosterone
What hormones are produced in kidneys
Renin: to help increase blood pressure if drops through the renin-angiotensin system
Erythropoietin: to increase RBC production if hypoxic
Prostaglandins: to help maintain renal perfusion
How does Kidney help with blood pressure regulation
Receptor monitor blood pressure
Renin
To help increase blood pressure when BP is low, through the renin-angiotensin system
the nephron of the kidney is and does what
The nephron is the functional unit
It is a microscopic, epithelial structure
Consists of a blood filtration unit attached to a long tube that absorbs and secretes to deliver urine as its end product
In order, the parts of the nephron are:
Bowman’s capsule (filtration)
Proximal Convoluted Tubule
Loop of Henle
Distal convoluted tubule
Collecting Duct
Where are the kidneys located
The kidneys are located in the abdominal cavity just to each side of the midline and are retroperitoneal (behind/outside of peritoneal cavity)
Generally, the right kidney is more cranially and dorsally than the left kidney
What does the kidney look like
A thick layer of fat surrounds and protects the kidneys
Called peritoneal fat
This allows us to visualize the kidneys on abdominal x-rays
Generally, the shape and color of kidney beans and smooth-surfaced
Capsule of the kidney is
a thin, but tough, connective tissue layer which surrounds the kidney
Hilus is what of the kidney
Located in the depression on the medial side of the kidney
The renal artery and nerves enter, and the ureter, renal vein and lymphatic vessels leave at the hilus
Renal pelvis is the
the expanded part of the ureter just inside the hilus
Receives urine from the collecting tubules of the kidney
Not found in cattle
Renal cortex is located
immediately beneath the capsule
Renal medulla is located and contains
Inner layer of kidney
Appears striated due to the arrangement of the collecting tubules
Also contains some loops of Henle (which contain the most concentrated fluid)
Renal cortex is
(aka papilla):
Ridge that projects into the renal pelvis .
The collecting tubules of medulla empty here.
Calyces are and do what
Funnels that medulla projects into
Direct fluid straight into the ureter
What does the bovine kidney look like
Kidneys are lobulated and do not have a renal pelvis or crest
Instead the ureter branches into each lobe and forms calyces, (calyx singular)
Porcine kidney shape
Also has calyces. Funnels fluid into the renal pelvis.
Nerve supply to the kidney
Supplied mainly by sympathetic nerves from the autonomic nervous system.
Sympathetic stimulation reduces renal blood flow
Not necessary for function: can rely on other controls (for example, if transplanted)
How much blood does the kidney get
The kidneys receive approximately ¼ of the cardiac output and convert about one thousandth of this into urine.
Renal artery is and goes where
enters the hilus
divide into smaller and smaller branches
become the afferent glomerular arterioles
What goes the afferent glomerular arterioles branch into
The afferent glomerular arterioles branch to form the glomerular capillary network of the renal glomerulus
Glomerular capillaries does what
Filter out some of the water and small molecules from the blood
The only capillary network in the body where blood is oxygenated going into and coming out